Temperature-control system



S. A. STAEGE TEMPERATURE CONTROL SYSTEM July 27, 1926;

I Filed July 13 MNJ ' INVENTOR Jip/len A WITNESSES: 51.53% 1/7)? 0 ATTORNEY Patented July 27, 1926.

UNITED STATES h r 1,594,128 PATENT OFFICE.

STEPHEN A. STAEGE, PITTSBURGH, PENNSYLVAN IA, ASSIGNOR TO WESTINGHOUSE ELECTRIC & MANUFACTURING COMPANY, A CORPORATION OF PENNSYLVANIA.

TEMPERATURE-CONTROL SYSTEM.

Application filed July 13, 1925. Serial No. 43,205.-

Y My invention relates to heating systems and particularly to means for controlling such systems.

One object of my invention is to provide a relatively simple and effective means for controlling the temperature of a heating system. Another object of my invention is to provide a temperature controlling device that shall embody motor-actuated means for effecting the energization of a plurality of heating units in step-by-step sequence and for varying the voltage supplied to the energized units between such steps.

In practicing my invention,.I provide a main heating unit and a plurality of auxiliary heating units.- The energization of the auxiliary heating units is controlled by a temperature-controlled motor-actuated induction regulator and means mechanically associated therewith for effecting the energization'thereof in predetermined sequence.

In the single sheet of drawings, Figure 1 is a view, partially in side elevation and partially in vertical longitudinal section, of a drying unit with which is associated a system embodying my inven-- tion, and

Fig. 2 is a schematic top plan view of apparatus and of a diagram of connections embodying my invention.

The system embodying my invention has been developed in connection with the drying of an initiall wet web of material, such as aper, an I have elected to'illustrate and describe the system 'as applied to such a method of drying. I ,do not desire,

- however, to be limited .to such use and application only, as the control method is applicable to a wide-range of .uses.

. A substantially enclosed casing 11 is built up in'anysuitable or desired manner to comprise the necessary frame work.and ;a pin? rality ofheat insulating walls that are pro-.

vided with an entering slot 12 and a leaving slot! 13 for a web of material 14 that is to be moved therethrough and dried therein. As the particular construction of the casing forms no part of my invention, it is illustrated schematically onl Means for supporting the initially wet web of material 14 within the casing and for effecting its passage therethrough, in a that are located one above another. The belts are made of fine mesh wire and are supported by relatively large drums or rollers 19 and 21 that are sultably supported adjacent to the two ends of the casing by any suitable means not shown). Means may also be provided for permitting movement of one of the rollers relatively'to the other inorder to obtain the proper tension on the endless belts. A plurality of smaller rollers 22 are so located relatively to the upper portion of each of the endless belts 15 to 18, inclusive, so that this portion will be located relatively closely to the lower portion of the endless belt located directly thereabove. The upper portion of the lower belt and the lower portion of the upper belt cooperate to receive and hold the'web of material therebetween and to move it back and forth in a plurality 'of passages while it. is being dried.

A plurality of. heating units are located between the upper and the lower portions of each of the belts except the upper one,

and severally comprise refractory members 24, of electric-insulating material, upon which is located a suitable resistor member 25 that is traversed by anelectric current to translate the energy into heat.

As the particular construction of the heating units forms no part of my invention,

,;rality of passes of the initially wet web of materlal.

The current traversing the respective resistor members 25 is of such a value as to raise the temperature of the fluid initially in the web to 212 F., then to transform the fluid into steam at that temperature, and then to further raise the temperature of the steam to a value which I have found by actual experiment to be of the order of 500 F. This temperature is high enough to produce a dry superheated steam within the casing 11 and this steam will be under I have not illustrated or described them a slight pressure relatively to the air sur-' rounding the casing. A conduit 26 maybe associated with the casing 11 through which the dry superheated steam may be ermitted to escape or through which it may e caused to flow into other devices wherein the heat in the steam may be profitably employed.

iliary web of material 14 moving past. this open side. An auxiliary heating unit 51 may be a After the dry web of material leaves the casing through the leaving slot 13, it is passed through a plurality .of calender rolls 27 and from there to a reeling device (not shown) of the usual kind.

The system embodying my invention has to do more particularly with a temperature controlling means by which I may obtain a predetermined degree of dryness of the web of material before it leaves the casing.

As hereinbefore' stated, it is preferable that the heating units be substantially unlforml distributed within the casing 11 and in or er to reduce'the size of the controlling .devices and of the amount of current or electric energy that must be controlled thereby, I prefer-to employ a main heating unit, or aplurality of main heating elements, that are connected to suitable supply circult conductors 28 and 29, the current supply being generally in the direction"of the arrow in Fig. 2, and controlled'through a suitable switch 31, .here illustrated as a'simple knife switch, but which Imay be of anysuitable or desired type and may include automatic circuit breakers.

The other distributed auxiliary heating units are energized through a plurality of contactors des1 ated by the numerals 32, 33, 34 and 35 ifiiistrated schematically only as comprisin a pair of cooperatin cont act membersan actuating coils there or. a

The operation of the respective contactors 32 to 35, inclusive, is reflected by a combined induction and step-by-step regulator 36. The reguflator 36 comprises a current coil 37 and a movable voltage coil 38 that are connected respectively into the circuit of the supply clrcuit conductor 29 and across the two supply circuit conductors in the usual manner.

' Means for causing a turning movement of the c011 38, comprises a motor armature-39 having two field windings 41 and 42 associated therewith. The motor shaft has a .worm 43-mounted thereon that is adapted to engage a worm gear 44 on an intermediate shaft 45, a second worm 46 being mounted thereon and engaging a worm gear 47 associated with the-movable coil 38.

While I have illustrated and described a particular embodiment of actuating and of mechanical'connecting means, I do not desire to be limited thereto as any motor-actuated means'e nployed in, the art may be used.

The energization of the field. windings 41 and 42 is controlled b a thermostatic member 48 that is prefe'ra ly located in an auxcasing 49 having one open side, the

located in the open-casin 49, and the thermostatic member 48 Wil efi'ect controlof the respective field windings 41 and 42 in accordance with the dryness of the web, of

material moving past the open casing 49. If the web of material has not been dried sufiiciently, .it will absorb a relatively large amount of heat from the auxiliary heating unit 51 and the temperature of the thermostatic member 48 will be reduced both by reason of the large amount of heat absorbed by the web of material and also by reason of its lower temperature. resulting from its higher fluid content. The useof the auxiliary casing 49 and of the thermostatic member 48 located therein is more particularly disclosed and claimed in my copending application Serial No, 27,670, filed Ma 4, 1925, and assigned to the Westinghouse lectric & Manufacturing Company.

A relatively short segment 52, of arcuate form and of electric-insulating material, has mounted thereon a luriility of contact members 53 that may e" of any suitable or desired formand that are respectively connected to one end of the actuating coils of the contactors 32 to 35, inclusive. A'seoond arcuate member 54, of electric-conducting material, or other such suitable. materialy is associated with the regulator 36 and is actuated by a suitable extension or projection 55 associated with the movin coil 38 and insulated therefrom. The pro ectiOn 55 has a'portion thereof fitting into a slot or groove 56, also of arcuate form, so that the member 54 will not be moved in a peripheral direction until the movable coil has been moved to substantially the extreme end of its travel.

It is evident that the maximum voltage .that'can be obtained by the use'of the induction regulator is. slightly lower when only one or two of. the contactors are energized than when they are all energized. This is for the reason that the arcuate member 54 will be in a position that is displaced in a clockwise direction from that shown, and the projection 55 will move to. the endof the slot 56 before the coil 38 has been moved to its maximum voltage position.

The operation of the system is substantially as follows: In starting the drying unit and the system, it is evident'that the term perature of the thermostatic control means 48 will be relatively low and that the free end thereof will operatively engage one of the contact terminals electricall connected to one of the respective field win ings 41 and 42that will result in so energizing the motor.

as to cause it to move the arcuate member 54 to such position that substantially all of the holding coils of the contactors provided in the system will be energized, the contactors will be in the closed position, and all of the heating units will also be energized. If the temperature should become too high, the thermostatic member 48 will so. move as to engage the other contact member wherebly the motor armature will actuate the movab e coil 38 in a direction to reduce which it s the voltage existing between the supply circuit conductor 28 and the ends or terminals of the respective heating units controlled by the contactors. The motor will continue to operate until the voltage supplied to all of the heating units energized at that time, with the exception of the main heating unit, Whose energization is controlled by the circuit interrupting means 31 and which is en ergized at a constant voltage, has been sufiiciently reduced to reduce the temperature to the desired value.

If the movable coil 38 and the projecting member 55 associated therewith is moved to such an extent that the portion thereof fitting into the arcuateslot 56 reaches the end of this slot, a further turning movement of the movable coil 38 will result in a peripheral movement 01' the arcuate member 54 until it has been disengaged from the first one of the contact members 53 which, in'

the illustration, is the one. at the upper end of the member 52. This disengagement of the electrid-conducting member 5a from one of the contact members 53 effects de-energization of the cooperating holding coil, thereby causing the contactor to open and to effect de-energization of the heating units controlled thereby.

It is possible that the de-energization of the heating units controlled by one of the contactors will very quickly result in lowering the temperature to a value below that desired to maintain in the casing 11. In this case, the thermostatic member 48 will again engage the other contact member and the motor will be energized in such manner as to eiiect a turning movement of the movable coil to increase the voltage applied to all of the heating unitsthen energized and controlled by the regulating means 36.

It will be noted, therefore, that the regulating ,means provided by my system comprises a step-by-step regulator, a plurality of auxiliary heating units, together wit means for varying the voltage applied to the heating units energized, with the exception of the main heating unit, in between the steps provided by the regulatin means.

The system provides thermally-controlled and motor-actuated, means for controlling the temperature ofa heating system in stepby-step sequence with intermediate induc tion regulator control, whereby aarticularly smooth regulation of the resulting temperature may be eflected.

Various modifications may be made without departing from the spirit and scope of my invention and all such modifications are intended to be included in the claims which are to be limited only by the prior art.

I claim as my invention:

1. A heating system comprising a main heating unit energized at constant voltage, a plurality of auxiliary heating units, and means for effecting energization of the auxiliary heating units at a variable voltage.

2. A heating system comprising a main heating unit, means for energizing the same at constant voltage, a pluralit of auxiliary heating units, and a therma ly-controlled, motor-actuated induction regulator for effecting energization of the auxiliary heating units at variable voltage and in predetermined sequence.

3. In a heating system, the combination with a main heating unit, and means for energizing the same at a constant voltage, of a plurality of individual, heating units, an motor-actuated means for energizing said heating units in step-by-step sequence and for varying the voltage supplied to the energized heating units to vary the amount of energy therein between said steps.

4;. In a heating system,

auxiliary heating units, and motor-actuate control means for said auxiliary units, said control means comprising an induction regulator forwarying the voltage supplied to the energized units, and means actuated thereby at one end of its travel for effecting energization of an additional heating unit.

5. In a heating system, the combination with a main heating unit, of a plurality of auxiliary heating units, and motor-actuated means for controlling the energization of said auxiliary units in sequence, said control means comprising an induction regulator for varying the Voltage supplied to the energized heating units, and means actuated thereby at one end of the travel of the movable portion of said induction regulator for effecting deenergization of one of said heating units.

6. A heating system comprising a plurality of heating units, and a temperaturecontrblled, motor-actuated induction regulatorfor varying the voltage applied to the heating units energized at any time, and means mechanically actuated by said regulator at one end of its travel for effecting energization of an additional heating unit.

7. A heating system comprising a plurality of heating units, a motor-actuated means for effecting energization of said heating units in predetermined steps, and inductive means actuated by the same motor for varying the amount of energy supplied tothe energized heating units between said steps. I 1

In testimony whereof, I have hereunto subscribed my name this 8th day of July 1925.

STEPHEN A. STAEGE.

use

the combination -with a main heating unit, of a plurality of 

